Trial: Chemo, antibody drug combo treats aggressive breast cancer

A trial found a combination of chemotherapy and antibody medications extended the lives of people with triple-negative breast cancer by up to 10 months. File Photo by CristinaMuraca/Shutterstock

Oct. 22 (UPI) -- A combination of chemotherapy and antibody medication extended the lives of people with triple-negative breast cancer by up to 10 months in a new trial.

Researchers led by Queen Mary University of London and St. Bartholomew's Hospital found that the combination helped the body's immune system turn back the aggressive type of breast cancer.
The method also reduced the risk of death or the cancer progressing by up to 40 percent, according to the study published Saturday in New England Journal of Medicine and presented at the European Society for Medical Oncology 2018 Congress in Munich, Germany.

"These results are a massive step forward," study leader Dr. Peter Schmid, professor of cancer medicine at Queen Mary University and clinical director of the Breast Cancer Center at St. Bartholomew's Hospital, said in a press release. "We are changing how triple-negative breast cancer is treated in proving for the first time that immune therapy has a substantial survival benefit."

Schmid said the process works "to tear away the tumor's 'immune-protective cloak' to expose it, as well as enabling people's own immune system to get at it."

In triple-negative breast cancer, the three most common types of receptors known to fuel most breast cancer growth -- estrogen, progesterone and the HER-2/neu gene -- are not present in the tumor. That means common treatments, like hormone therapy and drugs that target estrogen, progesterone, and HER-2, are ineffective.

Of all breast cancers,15 percent are triple-negative and hit mainly women in their 40s or 50s, according to the National Breast Cancer Foundation. Hispanic and African-American women and those with a BRCA-1 gene mutation are predominantly affected.

The standard treatment is chemotherapy. Most patients quickly develop resistance to it and if the disease spreads to other parts of the body, survival is often only 12 to 15 months.

The new treatment includes chemotherapy weekly and immunotherapy medication atezolizumab every two weeks. Atezolizumab is sold under the brand name Tecentriq by Roche, which funded the study.

Chemotherapy works by "roughening up" the surface of the cancer, which enables the immune system to better recognize cancer as a foreign object.

In the Phase 3 study, 902 women at least 18 were enrolled at 246 sites in 41 countries, including 230 in the United States, from 2015 to May 2017. Half were assigned atezolizumab and chemo, and the other half placebo and chemo.

Among those who received atezolizumab, they survived with no progression of cancer for a mean of 7.5 months. That's two months longer than women using chemotherapy and a placebo.

For women who tested positive for PD-L1 -- especially high levels of the protein -- they added another 2.5 progression-free months to their lives.

Adverse events occurred in 99.3 percent of patients in the atezolizumab group and in 97.9 percent in the placebo. Alopecia was the most common event in each group at around 57 percent followed by nausea at 46 percent in the atezolizumab group and 38 percent in the placebo one.

"Triple-negative breast cancer is an aggressive form of breast cancer; we have been desperately looking for better treatment options," Schmid said. "It is particularly tragic that those affected are often young, with many themselves having young families."